"Turn/set/put the clock back" are all idiomatic expressions that can mean to return to a previous era or time in history, or to undo progress that has been made. There are several synonyms that can be used in place of these phrases, such as "revert," "regress," and "retreat." "Revert" emphasizes the idea of going back to a previous state or condition. "Regress" suggests a decline or slide backward, often in terms of personal behavior or progress. "Retreat" implies withdrawal to a previous position or course of action. Regardless of the word choice, the underlying meaning is the same: going back to an earlier time or state.